exercises 06 done, onto structs

solutions/06_move_semantics/move_semantics4.rs

@@ -1,4 +1,19 @@
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn move_semantics4() {
+        let mut x = Vec::new();
+        let y = &mut x;
+        // `y` used here.
+        y.push(42);
+        // The mutable reference `y` is not used anymore,
+        // therefore a new reference can be created.
+        let z = &mut x;
+        z.push(13);
+        assert_eq!(x, [42, 13]);
+    }
 }